[ViewVC] Diff of: cvs/Coro/Coro.pm

Comparing Coro/Coro.pm (file contents):
Revision 1.1 by root, Tue Jul 3 02:53:34 2001 UTC vs.
Revision 1.23 by root, Mon Jul 23 04:23:32 2001 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	Coro - create an manage coroutines	3	Coro - coroutine process abstraction
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	use Coro;	7	use Coro;
8		8
		9	async {
		10	# some asynchronous thread of execution
		11	};
		12
		13	# alternatively create an async process like this:
		14
		15	sub some_func : Coro {
		16	# some more async code
		17	}
		18
		19	cede;
		20
9	=head1 DESCRIPTION	21	=head1 DESCRIPTION
10		22
		23	This module collection manages coroutines. Coroutines are similar to
		24	Threads but don't run in parallel.
		25
		26	This module is still experimental, see the BUGS section below.
		27
		28	In this module, coroutines are defined as "callchain + lexical variables
		29	+ @_ + $_ + $@ + $^W + C stack), that is, a coroutine has it's own
		30	callchain, it's own set of lexicals and it's own set of perl's most
		31	important global variables.
		32
		33	=cut
		34
		35	package Coro;
		36
		37	use Coro::State;
		38
		39	use base Exporter;
		40
		41	$VERSION = 0.10;
		42
		43	@EXPORT = qw(async cede schedule terminate current);
		44	@EXPORT_OK = qw($current);
		45
		46	{
		47	my @async;
		48
		49	# this way of handling attributes simply is NOT scalable ;()
		50	sub import {
		51	Coro->export_to_level(1, @_);
		52	my $old = *{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"}{CODE};
		53	*{(caller)[0]."::MODIFY_CODE_ATTRIBUTES"} = sub {
		54	my ($package, $ref) = (shift, shift);
		55	my @attrs;
		56	for (@_) {
		57	if ($_ eq "Coro") {
		58	push @async, $ref;
		59	} else {
		60	push @attrs, $_;
		61	}
		62	}
		63	return $old ? $old->($package, $ref, @attrs) : @attrs;
		64	};
		65	}
		66
		67	sub INIT {
		68	&async(pop @async) while @async;
		69	}
		70	}
		71
		72	=item $main
		73
		74	This coroutine represents the main program.
		75
		76	=cut
		77
		78	our $main = new Coro;
		79
		80	=item $current (or as function: current)
		81
		82	The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
		83
		84	=cut
		85
		86	# maybe some other module used Coro::Specific before...
		87	if ($current) {
		88	$main->{specific} = $current->{specific};
		89	}
		90
		91	our $current = $main;
		92
		93	sub current() { $current }
		94
		95	=item $idle
		96
		97	The coroutine to switch to when no other coroutine is running. The default
		98	implementation prints "FATAL: deadlock detected" and exits.
		99
		100	=cut
		101
		102	# should be done using priorities :(
		103	our $idle = new Coro sub {
		104	print STDERR "FATAL: deadlock detected\n";
		105	exit(51);
		106	};
		107
		108	# we really need priorities...
		109	my @ready; # the ready queue. hehe, rather broken ;)
		110
		111	# static methods. not really.
		112
		113	=head2 STATIC METHODS
		114
		115	Static methods are actually functions that operate on the current process only.
		116
11	=over 4	117	=over 4
12		118
13	=cut	119	=item async { ... } [@args...]
14		120
15	package Coro;	121	Create a new asynchronous process and return it's process object
		122	(usually unused). When the sub returns the new process is automatically
		123	terminated.
16		124
17	BEGIN {	125	# create a new coroutine that just prints its arguments
18	$VERSION = 0.01;	126	async {
		127	print "@_\n";
		128	} 1,2,3,4;
19		129
20	require XSLoader;	130	The coderef you submit MUST NOT be a closure that refers to variables
21	XSLoader::load Coro, $VERSION;	131	in an outer scope. This does NOT work. Pass arguments into it instead.
22	}
23		132
24	=item $main
25
26	This coroutine represents the main program.
27
28	=item $current
29
30	The current coroutine (the last coroutine switched to). The initial value is C<$main> (of course).
31
32	=cut	133	=cut
33		134
34	$main = $current = _newprocess {	135	sub async(&@) {
35	# never being called	136	my $pid = new Coro @_;
		137	$pid->ready;
		138	$pid;
		139	}
		140
		141	=item schedule
		142
		143	Calls the scheduler. Please note that the current process will not be put
		144	into the ready queue, so calling this function usually means you will
		145	never be called again.
		146
		147	=cut
		148
		149	my $prev;
		150
		151	sub schedule {
		152	# should be done using priorities :(
		153	($prev, $current) = ($current, shift @ready \|\| $idle);
		154	Coro::State::transfer($prev, $current);
		155	}
		156
		157	=item cede
		158
		159	"Cede" to other processes. This function puts the current process into the
		160	ready queue and calls C<schedule>, which has the effect of giving up the
		161	current "timeslice" to other coroutines of the same or higher priority.
		162
		163	=cut
		164
		165	sub cede {
		166	$current->ready;
		167	&schedule;
		168	}
		169
		170	=item terminate
		171
		172	Terminates the current process.
		173
		174	Future versions of this function will allow result arguments.
		175
		176	=cut
		177
		178	# this coroutine is necessary because a coroutine
		179	# cannot destroy itself.
		180	my @destroy;
		181	my $terminate = new Coro sub {
		182	while() {
		183	delete ((pop @destroy)->{_coro_state}) while @destroy;
		184	&schedule;
		185	}
36	};	186	};
37		187
38	=item $error, $error_msg, $error_coro	188	sub terminate {
		189	push @destroy, $current;
		190	$terminate->ready;
		191	&schedule;
		192	# NORETURN
		193	}
39		194
40	This coroutine will be called on fatal errors. C<$error_msg> and	195	=back
41	C<$error_coro> return the error message and the error-causing coroutine,
42	respectively.
43		196
44	=cut	197	# dynamic methods
45		198
46	$error_msg =	199	=head2 PROCESS METHODS
47	$error_coro = undef;
48		200
49	$error = _newprocess {	201	These are the methods you can call on process objects.
50	print STDERR "FATAL: $error_msg, program aborted\n";
51	exit 250;
52	};
53		202
54	=item $coro = new $coderef [, @args]	203	=over 4
55		204
56	Create a new coroutine and return it. The first C<resume> call to this	205	=item new Coro \&sub [, @args...]
57	coroutine will start execution at the given coderef. If it returns it
58	should return a coroutine to switch to. If, after returning, the coroutine
59	is C<resume>d again it starts execution again at the givne coderef.
60		206
		207	Create a new process and return it. When the sub returns the process
		208	automatically terminates. To start the process you must first put it into
		209	the ready queue by calling the ready method.
		210
		211	The coderef you submit MUST NOT be a closure that refers to variables
		212	in an outer scope. This does NOT work. Pass arguments into it instead.
		213
61	=cut	214	=cut
		215
		216	sub _newcoro {
		217	terminate &{+shift};
		218	}
62		219
63	sub new {	220	sub new {
64	my $class = $_[0];	221	my $class = shift;
65	my $proc = $_[1];	222	bless {
66	bless _newprocess {	223	_coro_state => (new Coro::State $_[0] && \&_newcoro, @_),
67	do {
68	eval { &$proc->resume };
69	if ($@) {
70	($error_msg, $error_coro) = ($@, $current);
71	$error->resume;
72	}
73	} while ();
74	}, $class;	224	}, $class;
75	}	225	}
76		226
77	=item $coro->resume	227	=item $process->ready
78		228
79	Resume execution at the given coroutine.	229	Put the current process into the ready queue.
80		230
81	=cut	231	=cut
82		232
83	my $prev;	233	sub ready {
84		234	push @ready, $_[0];
85	sub resume {
86	$prev = $current; $current = $_[0];
87	_transfer($prev, $current);
88	}	235	}
		236
		237	=back
		238
		239	=cut
89		240
90	1;	241	1;
91		242
92	=back	243	=head1 BUGS/LIMITATIONS
93		244
94	=head1 BUGS	245	- could be faster, especially when the core would introduce special
		246	support for coroutines (like it does for threads).
		247	- there is still a memleak on coroutine termination that I could not
		248	identify. Could be as small as a single SV.
		249	- this module is not well-tested.
		250	- if variables or arguments "disappear" (become undef) or become
		251	corrupted please contact the author so he cen iron out the
		252	remaining bugs.
		253	- this module is not thread-safe. You must only ever use this module from
		254	the same thread (this requirement might be loosened in the future to
		255	allow per-thread schedulers, but Coro::State does not yet allow this).
95		256
96	This module has not yet been extensively tested.	257	=head1 SEE ALSO
		258
		259	L<Coro::Channel>, L<Coro::Cont>, L<Coro::Specific>, L<Coro::Semaphore>,
		260	L<Coro::Signal>, L<Coro::State>, L<Coro::Event>.
97		261
98	=head1 AUTHOR	262	=head1 AUTHOR
99		263
100	Marc Lehmann <pcg@goof.com>	264	Marc Lehmann <pcg@goof.com>
101	http://www.goof.com/pcg/marc/	265	http://www.goof.com/pcg/marc/

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Comparing Coro/Coro.pm (file contents): Revision 1.1 by root, Tue Jul 3 02:53:34 2001 UTC vs. Revision 1.23 by root, Mon Jul 23 04:23:32 2001 UTC

Diff Legend

Comparing Coro/Coro.pm (file contents):
Revision 1.1 by root, Tue Jul 3 02:53:34 2001 UTC vs.
Revision 1.23 by root, Mon Jul 23 04:23:32 2001 UTC